Chair Base Assembly

ABSTRACT

A chair base assembly including a leg assembly, a seat support and a support column coupling the leg assembly to the seat support. Either one or both of the seat support and the leg assembly including an insert member that extends about a bore defined within each, configured to accept the support column. Such an insert member includes a winding that is outwardly deformable so as to be outwardly deformable. The insert member may include a winding of a substantially uniform wire-like member having a substantially uniform cross-sectional configuration so as to define a circular cross-section.

CROSS-REFERENCE TO RELATED APPLICATION

N/A

BACKGROUND OF THE DISCLOSURE

1. Field of the Disclosure

The invention relates in general to chairs, such as office chairs andthe like, and more particularly, to a chair base assembly having aconfiguration which provides enhanced assembly and enhanced durabilityto the overall construction. The disclosure is not limited to use inassociation with office chairs and the like.

2. Background Art

The use of chairs, such as office chairs is known in the art. Officechairs, and the like, generally include a seating component and asupport component. The seating component generally includes a typicallyhorizontal seating surface, a substantially vertical backrest andopposing armrests. Each of these elements may be independently ordependently adjustable so as to provide a custom fit to the user. Thesecomponents are each directly or indirectly coupled to a chair baseassembly and more particularly to a seat support member. The seatsupport member is generally a robust member which provides the interfacewith the remainder of the chair base assembly.

The chair base assembly includes the seat support member and a legassembly, with a support column coupling the two together. Each of theseat support member and the leg assembly include a bore that isconfigured to receive the opposing ends of the seat support member. Asthe structures tend to lighter and better performance materials, such aspolymers, certain problems have been identified.

Among other problems, the bore configured to receive the support columnin each of the leg assembly and the seat support tends to wear overtime. Once worn sufficiently, the bore may contribute to a dramaticfailure wherein the support column extends straight through the bore,collapsing the structure. Additionally, creep over time and deflectionunder high load can cause the support column to slip through the basesupport or the seat support.

A number of solutions have been provided including those disclosed inU.S. Pat. No. 5,692,715 issued to Hertel, U.S. Pat. No. 6,116,555 issuedto Claus et al, U.S. Pat. No. 5,149,035 issued to Bonnema et al and U.S.Pat. No. 5,377,943 issued to Perl. These solutions have provided someimprovement and resistance to failure.

Certain of the solutions include a molded and integrally formed insertmember which is generally of a material harder than the remainder ofeither the seat support or the leg assembly, such as, for example, ametal or alloy thereof. While such a solution has been helpful, thereare drawbacks. First, the metal member must be correctly sized withincertain tolerances. Second, it is often difficult to properly locate themember. Finally, the member is not flexible so as to be usable withdifferently sized support columns or differently configured legassemblies. There are other deficiencies with such configurations.

SUMMARY OF THE DISCLOSURE

The disclosure is directed to a chair base assembly. The chair baseassembly includes a leg assembly, a seat support and a support column.The leg assembly includes a central hub with a plurality of legsextending axially outwardly therefrom. The legs have a proximal endcoupled to the central hub and a distal end spaced axially outwardlytherefrom.

The central hub defines a cylindrical wall having an upper end and alower end. The cylindrical wall is inwardly tapered between the upperend and the lower end such that a cross-sectional configuration at theupper end is larger than a cross-sectional configuration of a portion ofthe cylindrical wall between the upper end and the lower end. Thecylindrical wall has an inner surface with a channel positioned betweenthe upper end and the lower end, with an insert member positioned withinthe channel. The insert member comprises a wound member configured toextend about the inner surface of the cylindrical wall at least a radialdistance that is greater than half of the circumference of the innerwall. The insert member is outwardly deformable.

The seat support is configured to receive at least one of a seatingsurface and a back rest. The support column has an upper end coupled tothe seat support and a lower end coupled to the leg assembly.

In a preferred embodiment, the insert member defines a generallycylindrical winding having a first end and a second end. The cylindricalwinding extends at least about the circumference of the inner surface ofthe cylindrical wall with the first end and the second end being offsetfrom each other and overlapping.

In another preferred embodiment, the insert member defines a cylindricalwinding having at least two full windings.

Preferably, the insert member is outwardly elastically deformed, andwherein the configuration is maintained by the coupling of the insertmember within the cylindrical wall of the central hub.

In another preferred embodiment, the insert member is positioned at theupper end of the cylindrical wall.

Preferably, the insert member comprises a winding formed from asubstantially uniformly configured metal member having a substantiallyuniform cross-sectional configuration.

In another preferred embodiment, the leg assembly further includes acaster positioned at the distal end of each of the legs of the legassembly.

In a preferred embodiment, the seat support further comprises a body anda seat support insert member. The body has a central bore defining aninner wall with a proximate end and a distal end. The channel ispositioned within the inner wall between the proximal and distal end.The seat support insert member comprising a wound member configured toextend about the inner surface of the central bore at least a radialdistance that is greater than half of the circumference of the innersurface. The seat support insert member is outwardly deformable.

In a preferred embodiment, the seat support insert member defines agenerally cylindrical winding having a first end and a second end. Thecylindrical winding extends at least about the circumference of theinner surface of the inner wall of the central bore with the first endand the second end being offset from each other so that they areoverlapping each other.

In another preferred embodiment, the seat support insert member definesa cylindrical winding having at least two full windings.

In yet another preferred embodiment, the seat support insert member isoutwardly elastically deformed. The configuration is maintained by thecoupling of the seat support insert member with the inner wall of thecentral bore.

In yet another preferred embodiment, the seat support insert membercomprises a winding formed from a substantially uniformly configuredmetal member having a substantially uniform cross-sectionalconfiguration.

In another aspect of the disclosure, the disclosure is directed to a legassembly for use in association with a chair assembly. The leg assemblycomprises a central hub with a plurality of legs extending axiallyoutwardly therefrom. The legs each have a proximal end coupled to thecentral hub and a distal end spaced axially outwardly therefrom. Thecentral hub defines a cylindrical wall having an upper end and a lowerend. The cylindrical wall is inwardly tapered between the upper end andthe lower end such that a cross-sectional configuration at the upper endis larger than a cross-sectional configuration of a portion of thecylindrical wall between the upper end and the lower end. Thecylindrical wall has an inner surface with a channel positioned betweenthe upper end and the lower end, with an insert member positioned withinthe channel. The insert member comprises a wound member configured toextend about the inner surface of the cylindrical wall at least a radialdistance that is greater than half of the circumference of the innerwall. The insert member is outwardly deformable.

In a preferred embodiment, the plurality of legs are integrally formedwith the central hub and comprise a polymer member. Additionally, theinsert member comprises a metal member which is formed from a windinghaving a substantially uniform cross-sectional configuration.

In another preferred embodiment, the insert member defines a generallycylindrical winding having a first end and a second end. The cylindricalwinding extends at least about the circumference of the inner surface ofthe cylindrical wall with the first end and the second end being offsetfrom each other and overlapping.

In a preferred embodiment, the insert member defines a cylindricalwinding having at least two full windings.

In another preferred embodiment, the insert member is outwardlyelastically deformed. Such a configuration is maintained by the couplingof the insert member with the cylindrical wall of the central hub.

In another preferred embodiment, the insert member is positioned at theupper end of the cylindrical wall.

In another aspect of the disclosure, the disclosure is directed to aseat support for use in association with a chair base assembly. The seatsupport includes a body and a seat support insert member. The body has acentral bore defining an inner wall with a proximate end and a distalend. A channel is positioned within the inner wall between the proximaland distal end. The seat support insert member comprises a wound memberconfigured to extend about the inner surface of the central bore atleast a radial distance that is greater than half of the circumferenceof the inner surface. The seat support insert member is outwardlydeformable.

In a preferred embodiment, the seat support insert member defines agenerally cylindrical winding having a first end and a second end. Thecylindrical winding extends at least about the circumference of theinner surface of the inner wall of the central bore with the first endand the second end being offset from each other so that they areoverlapping.

In a preferred embodiment, the seat support insert member defines acylindrical winding having at least two full windings.

In another preferred embodiment, the seat support insert member isoutwardly elastically deformed. The configuration is maintained by thecoupling of the seat support insert member with the inner wall of thecentral bore.

In a preferred embodiment, the seat support insert member comprises awinding formed from a substantially uniformly configured metal memberhaving a substantially uniform cross-sectional configuration.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will now be described with reference to the drawingswherein:

FIG. 1 of the drawings is a perspective view of a chair base of thepresent disclosure;

FIG. 2 of the drawings is an exploded perspective view of the chair baseof the present disclosure;

FIG. 3 of the drawings is a partial cross-sectional view of the legassembly of the present disclosure, showing, in particular, the centralbore thereof, taken generally about lines 3-3 of FIG. 1;

FIG. 4 of the drawings is a perspective view of the insert member of theleg assembly of the present disclosure;

FIG. 5 of the drawings is a partial cross-sectional view of the seatsupport of the present disclosure, showing, in particular, the centralbore thereof, taken generally about lines 5-5 of FIG. 1;

FIG. 6 of the drawings is a partial cross-sectional view of the chairbase of the present disclosure, taken generally about lines 3-3 of FIG.1; and

FIG. 7 of the drawings is a perspective view of the insert member of theseat support of the present disclosure.

DETAILED DESCRIPTION OF THE DISCLOSURE

While this invention is susceptible of embodiment in many differentforms, there is shown in the drawings and described herein in detail aspecific embodiment with the understanding that the present disclosureis to be considered as an exemplification and is not intended to belimited to the embodiment illustrated.

It will be understood that like or analogous elements and/or components,referred to herein, may be identified throughout the drawings by likereference characters. In addition, it will be understood that thedrawings are merely schematic representations of the invention, and someof the components may have been distorted from actual scale for purposesof pictorial clarity.

Referring now to the drawings and in particular to FIGS. 1 and 2, thechair base assembly is shown generally at 10. The chair base assembly 10is configured for use in association with, for example, an office chairor the like. The office chair typically includes a seating surface, aback rest and opposing armrests. The seating surface generally rests onthe seat support 16 which is coupled to the support column 14 and, inturn, to the leg assembly 12. The particular configuration of the officechair is generally not limited, and a number of different configurationsare contemplated.

The chair base assembly 10 includes the leg assembly 12, the supportcolumn 14 and the seat support 16. With additional reference to FIG. 3,the leg assembly includes central hub 20, legs 22, such as legs 22, andcasters, such as caster 24. It is contemplated that the central hub andthe legs 22 comprise an integrally molded polymer based member, althoughother configurations are also contemplated. The central hub 20 includescylindrical wall 30 and insert member 32. The cylindrical wall 30comprises an elongated configuration that includes an inner surface 38which spans between upper end 34 and lower end 36. The inner surface 38defines a central axis with a cross-sectional configuration along thelength thereof. At the upper end 34, the cross-section includes anenlarged portion with an upwardly directed upper flange 35 that extendsupwardly from the upper end 34. The inner surface 38 is generallytapered from the upper end 34 to the lower end 36. In the embodimentshown, below the upper flange 35, the inner surface is generally taperedtoward the lower end 36. That is, the diameter is larger at the upperend than at the lower end. In the embodiment shown, the taper betweenthe upper and lower ends is generally uniform and substantiallycontinuous. In other embodiments, the taper between the upper end andthe lower end may be non-uniform. In still other embodiments, the innersurface may include a step-down portion or portions so as to reduce thecross-sectional configuration in more abrupt manners.

The inner surface 38, proximate the upper end 34 thereof includeschannel 39 which is disposed into the surface. Insert member 32 ispositioned so as to be within the channel 39. The insert member 32, aswill be explained below, is positioned within the mold during themanufacturing process of the central hub. The insert member 32 comprisesa winding of material, generally a metal member, that has a windingdiameter that matches the cross-sectional configuration of the innersurface. With reference to FIG. 4, the insert member 32 includes firstend 27 and second end 29. In the embodiment shown, the insert membercomprises a metal winding that has approximately two full windings whenin an unstressed configuration. The metal winding is a steel memberhaving a cross-sectional configuration that is that of a generallycircular member with a predetermined diameter. In the embodiment shown,the diameter is approximately two inches, while a number of otherdiameters are likewise contemplated, and this is not to be deemedlimiting but, solely exemplary.

It will be understood that the insert member may comprise a winding ofmaterial that is of a different, uniform, or non-uniform cross-sectionalconfiguration. In addition, while two full windings are disclosed, itwill be understood that the insert member may include a greater orlesser number of windings. It is contemplated that the first and secondends 27, 29 of the insert member may be spaced apart from each other ormay overlap. In certain embodiments, the insert member may be as smallas a bit larger than half of the circumferential configuration of theinner surface proximate the channel 39.

Referring back to FIGS. 1 through 3, the legs 22 extend axially awayfrom the central hub in a spaced apart orientation generally equallyspaced about the central hub 20. While a number of differentconfigurations are contemplated, a total of between 4 and 6 legs iscontemplated. The leg 22 will be described with the understanding thatthe other legs are substantially identical to the leg 22.

Leg 22 extends from proximal end 40 at the central hub 20 to distal end42 spaced apart therefrom. The leg 22 extends in a generally downwarddirection from the proximal end to the distal end. The leg 22 generallycomprises a substantially inverted u-shaped configuration with leg upperbeam 44, first side wall 46 and second sidewall 48. Within the cavitydefined by the u-shaped configuration, a plurality of cross-supports 50are positioned thereacross in a spaced apart configuration. Thecross-supports 50 provide additional rigidity to the u-shapedconfiguration. The cross-supports may have a plurality of differentconfigurations. For example, they may extend in an intersectingcriss-cross configuration, or may extend generally parallel to eachother. A number of different configurations are contemplated.

As is shown in FIG. 3, a caster bore 52 is positioned at the distal end42 of the leg 22. The caster bore 52 is generally positioned so as to besubstantially parallel to the central hub 20 in a spaced apartconfiguration. Caster 24 includes caster axis 56 and caster wheelassembly 58. The caster axis 56 is offset relative to the axis rotationof the caster wheel assembly and perpendicular thereto. The caster axis56 is dimensioned so as to extend into the caster bore 52 of the distalend of the leg 22. Generally, an assembly is positioned on each of thecaster axis 56 and the caster bore 52 so as to capture and releasablylock the two structures together and to each other. In certainembodiments, the caster 24 may be replaced with a leg member thatprovides for a generally fixed configuration on the ground.

With reference to FIGS. 1, 2 and 7, the support column 14 comprises acylinder member that includes upper end 60 and lower end 64. Thecylinder member generally includes an outer wall configuration which maydefine several different cross-sectional configurations. The supportcolumn is configured to couple the seat support 16 to the leg assembly12. In certain configurations, the support column 14 comprises anadjustable member comprising multiple nesting cylinders. The differentcylindrical members can be adjusted pneumatically, hydraulically,mechanically, among other configurations. As will be explained below,the upper end 60 interfaces with the seat support 16 and the lower end64 interfaces with the central hub 20 of the leg assembly 12.

Seat support 16 is shown in FIGS. 1 and 5 as comprising body 70, centralbore 72 and insert member 74. The body 70 provides the support for theseating surface and the backrest, typically. Generally, the seat supportprovides the basis upon which the upper portion of the seat is coupledand configured. The body may comprise a molded polymer member, a metalmember, or a combination of members.

The central bore 72 extends into the body 70 and includes inner wall 77,proximal end 78, distal end 79 and channel 80. The inner wall includes agenerally conical configuration which tapers inwardly from the proximalend 78 to the distal end 79. The channel is generally molded into theinner wall so as to provide a receptacle for the insert member 74.

With reference to FIG. 6, the insert member 74 is much like the insertmember 32 of the leg assembly 12. The insert member is also positionedwithin the mold during the manufacturing process of the body 70. Theinsert member 74 comprises a winding of material, generally a metalmember, that has a winding diameter that matches the cross-sectionalconfiguration of the inner surface. The insert member 74 includes firstend 82 and second end 84. In the embodiment shown, the insert membercomprises a metal winding that has approximately two full windings whenin an unstressed configuration. The metal winding is a steel memberhaving a cross-sectional configuration that is that of a generallycircular member with a predetermined diameter. In the embodiment shown,the diameter is approximately one inch, while a number of otherdiameters are likewise contemplated, and this is not to be deemedlimiting but, solely exemplary.

It will be understood that the insert member may comprise a winding ofmaterial that is of a different, uniform, or non-uniform cross-sectionalconfiguration. In addition, while two full windings are disclosed, itwill be understood that the insert member may include a greater orlesser number of windings. It is contemplated that the first and secondends 82, 84 of the insert member may be spaced apart from each other ormay overlap. In certain embodiments, the insert member may be as smallas a bit larger than half of the circumferential configuration of theinner surface proximate the channel 80.

To manufacture the chair base assembly, the leg assembly is molded in aninjection molding press. Generally, the insert member 32 is positionedwithin the mold, around the portion that forms the cylindrical wall 30.When the polymer material is injected into the mold, the insert member32 is driven by the force toward the bottom of the mold, which is thelocation of formation of the upper end 34 of the cylindrical wall 30.The force of the molten material within the mold directs the insertmember to the desired location at the upper end 34. The insert member 32can elastically deform outwardly in the event that the cross-sectionalconfiguration of the insert member 32 is not within the desiredtolerance, so that it is pushed into the desired orientation. That is,advantageously, it is not necessary to size the insert member to thetolerances required for a ring member, as the insert member can bedeformed into the proper diameter during the molding process through theinjection of the material itself, or through the insertion process by auser.

Once molded, the insert member 32 will form the channel 39 and remainwithin the channel 39. In each instance, the insert member 32 has theproper and desired cross-sectional configuration and opening dimension,as well as the proper position within the molded member. Once fullyformed, the casters 24 can be assembled onto the respective one of thelegs, such as leg 22. In particular, the caster axis 56 of each casteris inserted into the corresponding caster bore 52 until each desiredcaser bore 52 includes a caster coupled thereto.

Similarly, the seat support is formed through an injection moldingpress, in a preferred embodiment. In such a configuration, the insertmember 74 is positioned within the mold. The injection of polymermaterial into the mold forces the insert member 74 toward the desiredorientation within the mold. If required, the insert member 74 isexpanded by the mold and through the force of the injected material.Once formed, the insert member 74 defines channel 80 and is integratedwith the seat support at the desired orientation.

In either instance, the insert member 32 and the insert member 74provide additional support to receive and capture the respective end ofthe support column 14 so as to engage the same at the desired location.In addition, the member is generally more resistant to wear than thesurrounding material, thereby providing additional durability to theconnection between the support column and the seat support and the legassembly and the seat support. In addition, through the configurationand elastic deformability of the insert member, the insert member can beconfigured to adapt (and during molding of the respective leg assemblyand seat support) to the precise desired configuration. Even whendeformed, the insert member has cross-sectional configuration thatprovides the necessary support within the cylindrical wall of thecentral hub, and also within the central bore of the seat support.

The foregoing description merely explains and illustrates the inventionand the invention is not limited thereto except insofar as the appendedclaims are so limited, as those skilled in the art who have thedisclosure before them will be able to make modifications withoutdeparting from the scope of the invention.

What is claimed is:
 1. A chair base assembly comprising: a leg assemblyhaving a central hub with a plurality of legs extending axiallyoutwardly therefrom, the legs having a proximal end coupled to thecentral hub and a distal end spaced axially outwardly therefrom, thecentral hub defining a cylindrical wall having an upper end and a lowerend, being inwardly tapered between the upper end and the lower end suchthat a cross-sectional configuration at the upper end is larger than across-sectional configuration of a portion of the cylindrical wallbetween the upper end and the lower end, the cylindrical wall having aninner surface with a channel positioned between the upper end and thelower end, with an insert member positioned within the channel, theinsert member comprising a wound member configured to extend about theinner surface of the cylindrical wall at least a radial distance that isgreater than half of the circumference of the inner wall, the insertmember being outwardly deformable; a seat support configured to receiveat least one of a seating surface and a back rest; and a support columnhaving an upper end coupled to the seat support and a lower end coupledto the leg assembly.
 2. The chair base assembly of claim 1 wherein theinsert member defines a generally cylindrical winding having a first endand a second end, the cylindrical winding extending at least about thecircumference of the inner surface of the cylindrical wall with thefirst end and the second end being offset from each other andoverlapping.
 3. The chair base assembly of claim 2 wherein the insertmember defines a cylindrical winding having at least two full windings.4. The chair base assembly of claim 3 where the insert member isoutwardly elastically deformed, and wherein the configuration ismaintained by the coupling of the insert member with the cylindricalwall of the central hub.
 5. The chair base assembly of claim 4 whereinthe insert member is positioned at the upper end of the cylindricalwall.
 6. The chair base assembly of claim 2 wherein the insert membercomprises a winding formed from a substantially uniformly configuredmetal member having a substantially uniform cross-sectionalconfiguration.
 7. The chair base assembly of claim 2 wherein the legassembly further includes a caster positioned at the distal end of eachof the legs of the leg assembly.
 8. The chair base assembly of claim 1wherein the seat support further comprises: a body having a central boredefining an inner wall with a proximate end and a distal end, a channelis positioned within the inner wall between the proximal and distal end;and a seat support insert member comprising a wound member configured toextend about the inner surface of the central bore at least a radialdistance that is greater than half of the circumference of the innersurface, the seat support insert member being outwardly deformable. 9.The chair base assembly of claim 8 wherein the seat support insertmember defines a generally cylindrical winding having a first end and asecond end, the cylindrical winding extending at least about thecircumference of the inner surface of the inner wall of the central borewith the first end and the second end being offset from each other andoverlapping.
 10. The chair base assembly of claim 9 wherein the seatsupport insert member defines a cylindrical winding having at least twofull windings.
 11. The chair base assembly of claim 10 where the seatsupport insert member is outwardly elastically deformed, and wherein theconfiguration is maintained by the coupling of the seat support insertmember with the inner wall of the central bore.
 12. The chair baseassembly of claim 9 wherein the seat support insert member comprises awinding formed from a substantially uniformly configured metal memberhaving a substantially uniform cross-sectional configuration.
 13. A legassembly for use in association with a chair base assembly comprising: acentral hub with a plurality of legs extending axially outwardlytherefrom, the legs having a proximal end coupled to the central hub anda distal end spaced axially outwardly therefrom, the central hubdefining a cylindrical wall having an upper end and a lower end, beinginwardly tapered between the upper end and the lower end such that across-sectional configuration at the upper end is larger than across-sectional configuration of a portion of the cylindrical wallbetween the upper end and the lower end, the cylindrical wall having aninner surface with a channel positioned between the upper end and thelower end, with an insert member positioned within the channel, theinsert member comprising a wound member configured to extend about theinner surface of the cylindrical wall at least a radial distance that isgreater than half of the circumference of the inner wall, the insertmember being outwardly deformable.
 14. The leg assembly of claim 13wherein the plurality of legs are integrally formed with the central huband comprise a polymer member, with the insert member comprising a metalmember which is formed from a winding having a substantially uniformcross-sectional configuration.
 15. The leg assembly of claim 13 whereinthe insert member defines a generally cylindrical winding having a firstend and a second end, the cylindrical winding extending at least aboutthe circumference of the inner surface of the cylindrical wall with thefirst end and the second end being offset from each other andoverlapping.
 16. The leg assembly of claim 15 wherein the insert memberdefines a cylindrical winding having at least two full windings.
 17. Theleg assembly of claim 16 where the insert member is outwardlyelastically deformed, and wherein the configuration is maintained by thecoupling of the insert member with the cylindrical wall of the centralhub.
 18. The leg assembly of claim 13 wherein the insert member ispositioned at the upper end of the cylindrical wall.
 19. A seat supportfor use in association with a chair base assembly comprising: a bodyhaving a central bore defining an inner wall with a proximate end and adistal end, a channel is positioned within the inner wall between theproximal and distal end; and a seat support insert member comprising awound member configured to extend about the inner surface of the centralbore at least a radial distance that is greater than half of thecircumference of the inner surface, the seat support insert member beingoutwardly deformable.
 20. The seat support of claim 19 wherein the seatsupport insert member defines a generally cylindrical winding having afirst end and a second end, the cylindrical winding extending at leastabout the circumference of the inner surface of the inner wall of thecentral bore with the first end and the second end being offset fromeach other and overlapping.
 21. The chair base assembly of claim 20wherein the seat support insert member defines a cylindrical windinghaving at least two full windings.
 22. The chair base assembly of claim21 where the seat support insert member is outwardly elasticallydeformed, and wherein the configuration is maintained by the coupling ofthe seat support insert member with the inner wall of the central bore.23. The chair base assembly of claim 20 wherein the seat support insertmember comprises a winding formed from a substantially uniformlyconfigured metal member having a substantially uniform cross-sectionalconfiguration.